var citys = citylist.citylist;
var sheng = document.getElementById("sheng");
for(var i in citys) {
	sheng.add(new Option(citys[i].p));
}

function setshi() {
	var citys = citylist.citylist;
	var index = document.getElementById("sheng").selectedIndex;
	var shi = document.getElementById("shi");
	shi.options.length = 0;
	if(citys[index].c[0].a) {
		for(var i = 0; i < citys[index].c.length; i++) {
			shi.add(new Option(citys[index - 1].c[i].n));
		}
	} else {
		shi.add(new Option(citys[index - 1].p));
	}
}